Clutch and brake device



Jan. 4, 1949. c MALMsTEN 2,457,907

CLUTCH AND BRAKE DEVICE 3 Sheets-Sheet; 1

Filed Sept. 25, 1946 lllll INVENTOR. 1%; C'//a/ms/en BY Jan. 4, 1949.

P. c. MALMSTEN CLUTCH AND BRAKE DEVICE 3 Sheets-Sheet 2 Filed S'ept. 23-, 1946 w 45 MM )W/orney Patented Jan. 4, 1949 Philip 0. Malmsten, Milwaukee, wis., assi nmto A. 0. Smith Corporation, Milwaukee, Wis., a corporation of New York Application September 23, 1946, Serial No. 698,651

1 Claim.

This inventionrelates to a clutch for stokers and has particular reference to a clutch for stokers which is employed in intermittently driving the stoker feed screw.

One object of the invention is to provide a 6 able. clutch for a Stoker which is substantially noise- The outer section Ill of the clutch housing is less and void of drag. free to rotate or oscillate circumferentially and Another object is to provide separate driving is assembled on bushing ring l2 which surrounds and holding rolls to prevent reversal of the stoker the outer portion of the cups-shaped clutch ratchworm after a stroke has been completed. et [3 which will be described hereinafter.

Another object is to provide a simple cage con- Housing section In is separated from inner secstruction for holding the rolls in place. tion 9 at the circumferential joint l4 therebetween Another object is to provide a clutch for a stoker to permit free oscillation of section III. Joint I4 is which is readily assembled and disassembled and sealed by the rubber gasket l5 which fits within a fabricated at generally low cost. l5 recess provided at the circumferential joint area These and other objects of the invention will of the housing sections. appear hereinafter in connection with the fol- The bracket l6 extends outwardly from rotatlowing description of the drawings illustrating an e hous and connecting od 2 1S ltembodiment of the invention. ably secured thereto and extends therefrom to the In the drawings: 1 transmission and motor unit, not shown, to rotate Figure 1 is a. longitudinal sectional view of the the n clutch assembly of a stoker; The clutch ratchet I3 is of generally circular Fig. 2 is an end view of Figure 1 with parts shape and is formed so that the forward portion broken away and sectioned; encircles bushing ll while the rear portion is Fig. 3 is an enlarged perspective view with parts directly mounted on spindle l. The rear portion broken away and sectioned of the cages for holdof. tc l i ott to receive shear pi 1 ing a, pair of driving and holding rollers with w ich ex ends transversely therethrou h and the bracket for securing them in place; through a matching aperture in spindle 4 to key Fig, 4 is a detail section showing th driving the ratchet and spindle together. Pin I I is held roll when the clutch is driving; in place by s ap ring 8.

Fig. 5 is a section similar to Fig. 4 showing he up-s ap d t on of rat t in the holding roll when the clutch is driving; bushing ll is provided on thecirciimferential face Fig. 6 is a detail section showing the driving thereof with a plurality of flat or cam faces I9 roll when the clutch is returning from the drivwhich are equa y Spaced around the circumfering stroke; and ence of the ratchet.

Fig. '7 is a section similar to Fig. 6 showing the The cages a rollers 2 which o p e the holding roll when the clutch is returning from the drive unit of the clutch are disposed on cam driving stroke. surfaces l9 of ratchet l3 within the oscillating Referring to the drawings there is illustrated a ou in section III. The cages 22 and rollers 2! portion of a stoker feed screw I which is driven 40 which comp the brake t of the lutch are intermittently from a transmission and motor, disposed on ca s r a s 9 wardly of cases not shown, through the connecting rod 2, the m and rollers and within the fixed hous n o1utoh assembly 3 and th pindle 4, section 9. Cages 20 and rollers 2|, and cages 22 Spindle 4 extends through th bearing plate 5 and rollers 23 are faced in the same direction which is secured t th housing 5 of th Stoker, '45 circumferentially around the ratchet l3 and are and the inner end of the spindle interlocks with interchangeable. the feed screw l to provide the driving connec- Cages 22 are generally angu ar tion therebetween. The spindle rotates within Shape h each of a pa r of cages 20 and 22 at bearing 1. Bearing I is located within bearing one end interlock with a bracket 24 which exhousing 8 which is disposed within the bearing tends circumferentially around ratchet II in one opening of plate 5. direction, and at the opposite end interlock with Spindle 6 extends a substantial distance outa corresponding r c t 24 which extends cirwardly from plate 5 and stokerhousing 6 to cumferentially around ratchet [3 in an opposite receive the clutch assembly 3. direction. The brackets 24 are secured to ratchet.

The clutch housing is formed of two generally 7 2 circular cup-shaped sections 9 and I0. The inner section 9 is welded to the outer face of bearing plate 5 and to the bushing ll within which spindle i rotates. Section 9 is fixed and non-rotatl3 by screws 25 or the like. The drawings illus- 3 trate three sets of cages and driving and holding rollers secured together on ratchet I3 and three corresponding cam surfaces l9.

Rollers 2| and 23 are retained in their respective cages by the transverse ears 26 and side ears 21 but are, free to rotate within their respective cages.

Cages 20 and 22 float separately of each other between brackets 24 but are biased in the driving direction of the clutch, shown as counter-clockwise in the drawings, by springs. 28. Each spring 28 has one end assembled over the tongue 29 of the bracket 24 to the right of the rollers 2| and 23 as shown in Figs. 4, 5, 6 and 7, and the other end of the spring engages the ear 26 of the cage 26 or 22 to bias the cage in the direction in which the clutch is driving ratchet l3. Suflicient clearance is provided at the interlocking Joints between cages 20 and 22 and brackets 26 to leave the cages freedom to float radially.

In the operation of the invention, as connecting rod 2 is pulled downwardly oscillating clutch housing section I is rotated thereby in a counter-clockwise direction. With this movement of housing ID the drive rollers 2| roll counter-clockwise on cam surface [9 and wedge between cam surface I9 of ratchet l3 and oscillating housing Ill and drive ratchet l3 in the direction of movement of housing H) as illustrated in Fig. 4.

When the clutch is driving as in Fig. 4, the holding rollers 23, as shown in Fig. 5, are slightly to the rear of driving rollers 2| and ride between the fixed housing 9 and cam surface I9. Since housing 9 is fixed, when ratchet |3 rotates, roller 23 is pinched radially in a clockwise direction and cage 22 compresses spring 28. Roller 23 thus rides freely on surface |9 and the inside of housing section 9 without wedging therebetween.

When the clutch is reversed upon return of rod 2 on completion of its driving stroke, ratchet I3 is held against turning. As shown in Figs. 6 and '7, the drive rollers 2| tend to roll'in a clockwise direction and compress spring 28 while the holding rollers 23 under the tendency of ratchet l3 to rotate are pinched in a direction opposite to drive rollers 2| and wedge between the ratchet and fixed housing 9 to prevent the ratchet from reversing.

The springs 28 maintain the respective sets of holding rolls and drive rolls in equal engagement with their respective housings and ratchet 3 and thus prevent excessive wear of any one roller by the same doing all the work.

By employing holding rolls separate from the drive rolls, drag on the clutch is prevented and noise is eliminated. The elimination of noise is particularly important in the use of the clutch with stokers.

The construction of the clutch is simple and costs are held to a minimum since the flat cam surfaces of the ratchet are employed for both the driving and holding rolls of the clutch. At the same time the cage, rollers, springs and brackets are interchangeable regardless whether they are employed as driving means or holding means, and therefore can be produced in lots at relatively low costs.

Various embodiments of the invention may be employed within the scope of the accompanying claim.

I claim:

In a clutch unit for communicating intermittent rotary movement to a driven member, a housing encircling said driven member and separated axially of the member into a fixed section and an oscillating section, a cam surface provided longitudinally of said driven member, separate cages disposed on said cam surface with a freely rotatable drive roller confined in one cage beneath the rotatable section of the housing and a corresponding braking roller confined in the other cage beneath the fixed section of the housing, a common bracket securing said cages to the driven member and leaving the cages free to reciprocate independently of each other transversely of said cam surface, and a spring disposed between said bracket and each cage to bias the rolls to wedging action between the cam surface and their respective housing to intermittently drive and brake the driven member upon oscillation of the oscillating housing section.

PHILIP C. MALMSTEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,222,712 Armstrong Apr. 1'7, 191'? 1,544,621 Widmann July 7, 1925 1,719,613 Kohler July 2, 1929 2,360,075 Schoij Oct. 10, 1944 

